A gas turbine engine may be used to supply power to various types of vehicles and systems. For example, gas turbine engines may be used to supply propulsion thrust or power for various types of vehicles, including aircraft and helicopters. Also, a gas turbine engine may be used as an auxiliary power unit (APU) to provide electrical power or compressed air to an aircraft. Generally, gas turbine engines include at least three major sections: a compressor section, a combustor section, and a turbine section. The compressor section receives a flow of intake air and raises the pressure of this air to a relatively high level. The compressed air from the compressor section then enters the combustor section, where fuel nozzles inject a steady stream of fuel. The injected fuel is ignited by a burner, which significantly increases the temperature of the compressed air. The high-temperature compressed air from the combustor section then flows into and through the turbine section, causing rotationally mounted turbine blades to rotate and generate power. The air exiting the turbine section is then exhausted from the engine. In a multi-spool engine, the turbine section may include a plurality of turbines. The mechanical power generated in each of the turbines may be used to rotate other portions of the engine, such as a generator to produce electrical power, as well as providing propulsive thrust.
Typically, gas turbine engines are configured so as to operate most efficiently during “cruise” operations, that is, at engine speeds typically used during the cruise portion of the vehicle operation. While gas turbine engines are optimized for cruise, during certain flight phases, such as take-off and descent, and other transient operations, the engine may operate in a sub-optimal condition. Sub-optimal operation increases fuel burn, and therefore leads to an increased expense of operation.
Hence, there is a need for a system and a method that alleviates the above-noted deficiencies in the prior art. Furthermore, other desirable features and characteristics of the inventive subject matter will become apparent from the subsequent detailed description of the inventive subject matter and the appended claims, taken in conjunction with the accompanying drawings and this background of the inventive subject matter.